Spatial Mapping of Electrostatic Fields in DHFR

描述（由申请人提供）： 静电场和静电势是了解蛋白质结构和功能的有用概念。拟议的研究的目的是建立一个实验路线，提供直接测量的本地静电场的蛋白质的实质性药理学利益，二氢叶酸还原酶（DHFR）。本文采用的策略将利用无义抑制和振动斯塔克效应（VSE）光谱学：使用无义抑制技术将带有适当VSE探针部分的非天然氨基酸掺入DHFR中。然后利用振动斯塔克效应，描述为由于电场的存在而导致的振动跃迁的能量转移，以将存在于非天然氨基酸内的简单分子功能性转化为局部静电场的小的高度局部化的探针。由此产生的实验测量可以提供深入了解静电相互作用对蛋白质结构和功能的影响，也可以建立实验数据和理论计算之间的直接联系，这反过来又可能导致合理的药物设计的理论方法的改进。

DESCRIPTION (provided by applicant): Electrostatic fields and electrostatic potentials serve as useful concepts to gain insight into protein structure and function. The objective of the proposed research is to establish an experimental route that provides direct measurements of local electrostatic fields in a protein of substantial pharmacological interest, dihydrofolate reductase (DHFR). The strategy employed here will utilize nonsense suppression and vibrational Stark effect (VSE) spectroscopy: non-natural amino acids bearing appropriate VSE probe moieties will be incorporated into DHFR using nonsense suppression techniques. The vibrational Stark effect, described as a shift in energy of a vibrational transition due to the presence of an electric field, is then utilized in order to transform the simple molecular functionality that exists within the non-natural amino acid into a small, highly-localized probe of local electrostatic fields. The resulting experimental measurements may afford insight into the influence of electrostatics interactions on protein structure and function and, also, may establish a direct link between experimental data and theoretical calculations which, in turn, may lead to improvements in theoretical methods for rational drug design.